Boiler



II. HAIIDING,

BOILER.

APPLICATION FILED III/m13, |922.

9433;5961l Patented Deo. 12, 1922.

f". y n y IIJ' a a ATTO RN EY HARVEY HARDIN G, OF EST ORANGE, NEW JERSEY.

1 BOILER.

.Application led/Mach 13, 1922. Serial No. 543,284.

To @ZZ whom t may oon-cern.'

Be it known that I, HARVEY HARDING, a. citizen of the United States, residing at East Orange, in the county of Essex and State of New Jersey, have invented new and useful Improvements in Boilers, of which the following is a specification.

This invention relates to improvements in boilers, and the principal object is to devise means whereby the tubesmay be rendered v electro-negative for a considerable portion or all of their length without interfering with the expansion and contraction of the tube connections which has been-found in practice to be essential.

Another object is to so arrange contacting metals as to render the tubes electro-negative and thereby prevent pitting of the same.

`With these and other objects in view, the invention resides in certain construction, the essential features of which are hereinafter fully described, are particularly pointed out in the appended claims, and are illustrated in the accompanying drawing, in which Figure 1 is a fragmentary View ofa portion o f a boiler, showing the manner of sup'- porting a tube. y

Figure 2 is an exaggerated detail. view `of 'the means of securing a tube in place.

' Like charactersof reference refer to like .parts in both views.

1 In' the tubes of locomotive'boilers, ship boilers,and the like it has been demonstrated that owing to the heating of the end of' the tube 10 near the firebox 11, and thefact -that this end of the tube is mounted in a collar 12 of copper or brass to permit of rapid expansion and., contraction, thermoelectric currents-are set up near the rebox.

As the tubes are surrounded by water which in most instances becomes more or less impure so as to-act as an electrolyte, the eurrent flowing from the tube to the collar Vsets up anelectrolysis whereby the tube is --pitted. The tubetherefore is quickly rendered unserviceable,.and it is then necessary to insert an entire new tube or to cut off thel pitted portion and weld on a new piece in its place.'

This pitting of the tube has been knownfor some time to be dueto electric activity, but it has been supposed 'that this was of galvanic nature as between variousfparticles in the tube. However, it will be readily seen that the thermo-electric action is responsible foi-athis, when it isremembered that the steel tube'is Iseated in a copper c ol ing the copper plate isv greatly exaggerated lin the showing in Figure 2 and is indicated lar, and corresponds to the similar construction used inpyroineters. To overcome this condition, the only thing that has been so f ar attempted with any degree of success has been the treatment of the water so as to remove its electrolytic action. But the difficulty with 'this method is that it must be one-hundred per cent perfect -in analysis and action if it is not to do more harm than good. If a few percent toomuchof the treatment mixture vis added to the water,.then the boiler will foam, greatlyreducing the efficiency of the steam; and if too littlelis used a coating of'lime will be formed o n the tubes.l Also the expense in keeping up e the necessary chemical laboratories and u equipment is well-nigh prohibitive.-

ltheir entire lengthofI to such an extent as will entirely copper the portion of the tubes which is subject -to thermo-electric .action from the heat of the lire box. In the draw-4 by the numeral 14. The copper plate of the tube being in contact with the copper collar 12, no thermo-electric cur-rents are set up. and the pitting of the tube is thereby eliminated, and the tube will notbecomejcoated" with lime or other shell, while, at the same g time, the essential expansion and contraction lof the tube connection is not interfered with. It will be seen that by my novel means I` have produced tubes and tube connections for. boilers, which Will resist decomposition and effectually eliminate galvanic or thermoelectric i action Ior oxidation without interfering with the essential expansion and con'- traction of the connections.

What is claimed as-new is:-

1. The combination in a boiler construction, of an apertured tube sheet, flue tubes extending transversely'through the apertures of the sheet and' secured at one end -toI the sheet, copper collars lining the apertures of the tube sheet, and coatings of copper on and exterior of the tubes and extending a distance from the tube sheet and interposed between the said tubes and the copper collars, whereby withoutl interfering with they essential expansion and contraction of the." tube connections passage of electriccurrent from the tubes through the water to the 110 collarsis prevented.-

2;.The combination in a boiler construction of an apertured tube sheet', ue tubes from the tube sheet whereby without inextending transversely through the apertures terfering With the lessential expansion and 10 of the sheet and secured at one end to the contraction of the tube connections passage sheet, and copper collars lining the apertures of electric:v current from the tubes throughv 5 of the tube Vsheet and surrounding the Hue the Water t0 the collars s'prevented. tubes; the said flue tubes being exteriorlyA In testimony whereof l have affixed my copper plated throughout the interiorV of the signature. v v

, copper collars and for a distance inwardly A HARVEY'HARDING 

